The researchers at CO2 Science recently summarized a 2017 study in the journal Climate that indicates across geologic history, the level of atmospheric carbon dioxide has had no relation to temperature or climate conditions.
The study’s author, W. Jackson Davis, Ph.D., executive director of the Environmental Studies Institute, analyzed a comprehensive assemblage of empirical databases consisting of 6,680 proxy temperature and 831 proxy carbon dioxide measurements to examine the relationship between historic temperature and atmospheric carbon dioxide from 522 million years before present (Mybp) to now. Davis says his data assemblage is “the most accurate quantitative empirical evaluation to date of the relationship between atmospheric CO2 concentration and temperature.”
Davis found neither a causal association nor a correlation between carbon dioxide levels temperatures over millions of years.
“For example, Davis reports, (1) ‘a carbon dioxide concentration peak near 415 My[bp] occurs near a temperature trough at 445 Mybp,’ (2) ‘similarly, carbon dioxide concentration peaks around 285 Mybp coincide with a temperature trough at about 280 My[bp] ....’” Ultimately, Davis concludes “more than 95 percent of the variance in temperature [across millions of years] is explained by unidentified variables other than the atmospheric concentration of carbon dioxide,” which Davis writes, “corroborate the earlier conclusion based on study of the Paleozoic climate that ‘global climate may be independent of variations in atmospheric carbon dioxide concentration,’” the summary reports.
Davis concludes although “correlation does not imply causality, but the absence of correlation proves conclusively the absence of causality.”
Source: CO2 Science